Staple gun



FIG. 1 is a perspective view of a staple gun showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a top side elevational view thereof;

FIG. 4 is a bottom side elevational view thereof;

FIG. 5 is a front side elevational view thereof; and,

FIG. 6 is a rear side elevational view thereof.

The claimed portion of the staple gun is understood to be defined as those areas that are shown with surface shading. The broken lines form no part of the claimed design. 

The ornamental design for a staple gun, as shown and described. 